The screening of incoming calls is important to cellular telephone users because many cellular-telephone subscriber plans provide for billing subscribers for incoming-answered, as well as outgoing, calls. The subscriber who knows the identity of the incoming caller can choose to answer only those incoming calls for which the subscriber wishes to pay. Moreover, the subscriber who knows the identity of the incoming caller can choose to answer the call or allow the incoming caller to leave a voice message depending upon the subscriber's priorities, time constraints, and other considerations.
There are several methods and products that allow the user of a telephone to screen incoming calls. U.S. Pat. No. 5,473,671 to Partridge cites some of them and explains their disadvantages, and its disclosure is incorporated by reference. Answering machines are probably the most popular method of call screening in use today. One of the disadvantages of the answering-machine method is that a connection is made between the incoming caller and the answering machine even if the incoming call is unwanted. In a cellular system, the user of an answering machine might pay for the time the incoming caller takes to leave a message. The “Caller ID” feature is also a popular method of call screening. Among the disadvantages of the “Caller ID” feature is that some systems provide for identifying only the telephone number from which the incoming call originates. Also, state of the art cellular systems do not provide the “Caller ID” feature.
U.S. Pat. No. 5,473,671 to Partridge discloses an invention for selectively screening incoming calls for cellular telephone systems. The invention disclosed therein maintains a preselected list of caller identities, such as telephone numbers. The user predesignates treatment for each identity, such as forward to the user's cellular telephone, offer the caller the option of paying for the call, or other treatment. An incoming call is compared to the preselected list and is treated in the manner predesignated. One of the disadvantages of this invention is that it requires predesignation of treatment. It does not allow the user to make dynamic decisions regarding how to treat the incoming call based upon the user's needs and desires at the time of the incoming call.
U.S. Pat. No. 5,559,860 to Mizikovsky discloses an invention for screening incoming calls at a mobile station. In a manner similar to the invention disclosed in U.S. Pat. No. 5,473,671, the invention disclosed therein compares the incoming call to a preselected list containing calling party identification data and corresponding predesignated response categories. The invention responds to the incoming call in the manner indicated by the preselected list. This invention has the same disadvantages as those of the invention disclosed in U.S. Pat. No. 5,473,671. In particular, dynamic decisions by the user are not permitted.